Method for preparing an air-fuel mixture for an internal combustion engine, device for realizing the same and heat-exchanger

Abstract

The present invention pertains to the field of engine construction and may be used in the inlet systems of internal combustion engines for processing a portion of the rich air-fuel mixture fed into the main flow, wherein the liquid fuel is pulverised and converted into gas. The purpose of this invention is to increase fuel savings, to reduce the exhaust gas toxicity and to enable the use of a cheaper low-octane fuel. The method for preparing the air-fuel mixture comprises using the heat from the hot gases produced for heating the excessively rich mixture flow that contains between 10 and 100% of petrol to be used by the engine, wherein said heating is carried out before mixing the mixture with the second flow. The mixture is then submitted in one or more steps to the thermal action of activators with compensation for the air used during the reactions. The device of the present invention comprises a heat exchanger ( 1 ) as well as a unit for dosing the mixture components ( 2 ), wherein said unit is connected by an inlet duct ( 5 ) to the mixture circuit through which said mixture is fed into a chamber ( 3 ) with an activator ( 4 ). The hot gases are generated in this chamber and flow through the inlet duct ( 6 ) of the gas circuit as well as through the outlet duct ( 7 ) thereof into the engine inlet system. The activator ( 4 ) chamber is connected to a pipe ( 8 ) and to a plurality of nozzles ( 9 ) for supplying additional air to the activator. The heat exchanger includes a body having an embossed partition therein that defines a plurality of cells-channels for the flow of the heat-carrier and the heating medium, wherein the walls of each cell-channel are connected together at their end portion up to half the height of the channel.

What is claimed is:  
     
       1. A method for preparing fuel-air mixture for internal combustion engines, consisting in establishing two flows of the fuel-air mixture of which one gets overrich below the ignition range, preheating said overrich flow to produce carbon monoxide and hydrogen-containing gases, and mixing said flow with the other flow of mixture before feeding said flows of mixture to the engine cylinders, CHARACTERIZED in that the overrich flow of the fuel-air mixture containing 10 to 100% of the fuel consumed by the engine is subjected to single- or multi-stage thermal action by a promoter and the air spent for reactions is compensated for either partially or completely. 
     
     
       2. The method of claim  1 , CHARACTERIZED in that the spent air is compensated for by being fed into the flow of mixture downstream of the promoter. 
     
     
       3. The method of claim  1 , CHARACTERIZED in that the flow of overrich fuel-air mixture is preheated by the heat of the resultant hot oil gases, thereby reducing the temperature of said gases before feeding them to the engine. 
     
     
       4. A device for preparing fuel-air mixture for internal combustion engines, comprising a double-loop heat-exchanger having an inlet piping and an outlet piping, a mixture-handling loop, a gas-handling loop, a promoter chamber, and a proportioner of the mixture components, the inlet of the mixture-handling loop being connected to the proportioner of the mixture components and to the promoter chamber, CHARACTERIZED in that the inlet and outlet pipings of the gas-handling loop are connected to the promoter chamber and the inlet duct of the engine for fuel-air mixture, and the promoter chamber accommodates additional air feeding nozzles. 
     
     
       5. The device of claim  4 , CHARACTERIZED in that the promoter is of the multistage design and appears as successively arranged sections, and the air nozzles are provided past each of said sections.